Resonantly enhanced real hyperpolarizability.

We show theoretically and experimentally how the first hyperpolarizability of a three-level molecule at a two-photon resonance can obtain a real value with strong resonant enhancement. This phenomenon arises from destructive interference of the usually dominant imaginary parts of the resonant hyperpolarizability.

[1]  S. Harris,et al.  Light speed reduction to 17 metres per second in an ultracold atomic gas , 1999, Nature.

[2]  M. S. Shahriar,et al.  Efficient phase conjugation via two-photon coherence in an optically dense crystal , 1999 .

[3]  Kajzar,et al.  Electric-field-induced optical second-harmonic generation in polydiacetylene solutions. , 1987, Physical review. A, General physics.

[4]  S. Harris,et al.  Lasers without inversion: interference of dressed lifetime-broadened states. , 1989, Optics letters.

[5]  Z. Kotler,et al.  Measurement and analysis of molecular hyperpolarizability in the two-photon resonance regime , 2000 .

[6]  J. Oudar,et al.  Hyperpolarizabilities of the nitroanilines and their relations to the excited state dipole moment , 1977 .

[7]  M. C. Flipse,et al.  Nonlinear contrawave mixing devices in poled-polymer waveguides , 1998 .

[8]  U. Fano.  Effects of Configuration Interaction on Intensities and Phase Shifts , 1961 .

[9]  D Bloor,et al.  Near-resonant refractive nonlinearity in polydiacetylene 9-BCMU thin films. , 1993, Optics letters.

[10]  Brian J. Orr,et al.  Perturbation theory of the non-linear optical polarization of an isolated system , 1971 .

[11]  S. Jenekhe,et al.  Dispersion of the third-order nonlinear-optical properties of poly(p-phenylene benzobisthiazole) and its molecular composites with polyamides , 1992 .

[12]  Lev Shapiro,et al.  Effect of carbazole as a donor moiety on the second-order nonlinearity of organic molecules , 1999, Optics & Photonics.